SILICA-ON-SILICON WAVEGUIDES AND RELATED FABRICATION METHODS

• US 20090285542A1
• Filed: 05/07/2009
• Published: 11/19/2009
• Est. Priority Date: 05/19/2008
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: PAINTER, Oskar, VAHALA, Kerry, MARTIN ARMANI, Andrea
• Granted Patent: US 8,045,834 B2
• Time in Patent Office: Days
• US Class Current: 385/146
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 2006/12038 Glass (SiO2 based materials)
• CPC Class Codes: G02B 2006/12119 Bend
• CPC Class Codes: G02B 6/1223 high refractive index type, i.e. high-contrast waveguides
• CPC Class Codes: G02B 6/13 Integrated optical circuits characterised by the manufacturing method
• CPC Class Codes: G02B 6/2861 using fibre optic delay lines and optical elements associated with them, e.g. for use in signal processing, e.g. filtering delay lines in general H03H, H01P9/00; optical computing devices G06E

Abstract

True time delay silica waveguides and related fabrication methods are disclosed. Also disclosed are true time delay silica waveguides comprising wedged silica structures.

Claims

1. A silica waveguide, comprising:

a first silica waveguide structure;

a second silica waveguide structure;

a silica separation strip separating the first silica waveguide structure from the second silica waveguide structure; and

a silicon pillar supporting the first silica waveguide structure, the second silica waveguide structure, and the silica separation strip.

2. The silica waveguide of claim 1, wherein the first silica waveguide structure is parallel to the second silica waveguide structure.

3. The silica waveguide of claim 2, wherein the silica separation strip is substantially rectangularly shaped.

4. The silica waveguide of claim 1, wherein the silica separation strip is substantially polygonally shaped.

5. The silica waveguide of claim 1, wherein the first silica waveguide structure defines a first waveguide and the second silica waveguide structure defines a second waveguide, the first waveguide being separate from the second waveguide.

6. The silica waveguide of claim 1, wherein the first silica waveguide structure defines a first portion of a waveguide and the second silica waveguide structure defines a second portion of the waveguide.

7. The silica waveguide of claim 6, further comprising an input port and an output port, the input port and the output port being located together.

8. The silica waveguide of claim 5, wherein the first waveguide and the second waveguide operate ad different wavelengths.

9. The silica waveguide of claim 1, wherein the first silica waveguide structure and the second silica waveguide structure extend along a curved path.

10. The silica waveguide of claim 9, wherein the curved path is a spiral path.

11. A method for fabricating a silica waveguide, comprising:

defining a substantially polygonal silica pad on a silicon substrate;

performing a laser silica reflow process on the silica pad; and

, after that,

cleaving at least one of the sides of the silica pad to define two non-resonant waveguide structures.

12. The method of claim 11, wherein cleaving at least one of the sides of the silica pad comprises cleaving one side of the silica pad to define a single, substantially C-shaped, waveguide structure.

13. The method of claim 11, wherein cleaving at least one of the sides of the silica pad comprises cleaving two sides of the silica pad to define two separate waveguide structures.

14. The method of claim 11, wherein the polygonal silica pad is a rectangular or square silica pad.

15. The method of claim 11, wherein the substantially polygonal silica pad is defined through etching.

16. The method of claim 11, wherein the laser silica reflow process is performed by movement of the silica pad through a laser beam.

17. The method of claim 11, wherein the laser silica reflow process is performed by movement of a laser beam through the silica pad.

18. The method of claim 11, wherein the two waveguide structures extend along a curved path.

19. The method of claim 18, wherein the curved path is a spiral path.

20. A silica waveguide having a substantially curved shape, comprising:

a first curved waveguide;

a second curved waveguide; and

a transition section connecting the first curved waveguide with the second curved waveguide,

wherein the first curved waveguide, second curved waveguide, and transition section are wedged silica structures forming a non-resonant silica waveguide.

21. The silica waveguide of claim 20, wherein the first curved waveguide, second curved waveguide, and transition section are embedded wedged silica structures.

22. The silica waveguide of claim 21, wherein the embedded wedged silica structures are embedded in a material having a refractive index higher than air and lower than a refraction index of the silica structures.

23. The silica waveguide of claim 20, wherein the first curved waveguide, second curved waveguide, and transition section are double wedged silica structures.

24. The silica waveguide of claim 20, wherein the silica waveguide is coupled to one or more adiabatic couplers.

25. The silica waveguide of claim 20, wherein the first curved waveguide is a first spiral waveguide and the second curved waveguide is a second spiral waveguide, and wherein the silica waveguide has a substantially spiral shape.

26. The silica waveguide of claim 20, the silica waveguide being arranged in a multiple pattern of vertically coupled silica waveguides.

27. The silica waveguide of claim 20, wherein the transition section comprises an inflection point.

28. The silica waveguide of claim 20, wherein the transition section is connected to the first curved waveguide and the second curved waveguide through adiabatic transitions separated by a single mode waveguide.